A Technical Report is purely informative. It contains data and methods that are still under development or are too specialized for a full standard. However, in thermal gear analysis, ISO TR 14179-2 is treated as the industry reference.
Part 2 provides empirical formulas for no-load losses (churning, windage, seal drag). These losses depend on:
Let’s walk through a typical use case for the ISO TR 14179-2 pdf.
Scenario: You need to select a gearbox for a conveyor system. Motor power = 45 kW, output speed = 30 RPM, ambient temperature = 40°C, altitude = 1500m.
Common misuse: People take the thermal power numbers from Part 1 and ignore Part 2’s correction factors, then wonder why their gearbox fails at 110°C. iso tr 14179-2 pdf
Correct, insightful use: A designer uses TR 14179-2 to back-calculate the effective thermal resistance of their housing geometry. The PDF includes separate factors for:
Pro tip from the field: The standard reveals that painting a gearbox matte black vs. glossy gray can improve heat radiation by 18-22% – more than adding a small fan in many cases.
Most gearbox designers obsess over tooth bending stress (ISO 6336) or pitting resistance. But the silent killer of gearboxes isn't stress—it's heat. Every year, millions of dollars are lost to lubricant coking, tooth scuffing, and oil seal failure caused by underestimated thermal loads.
Enter ISO TR 14179-2:2007 – the "Technical Report" that is anything but boring. While Part 1 of the standard gives you the thermal balance equations, Part 2 is the secret weapon: a massive library of thermal dissipation data for real-world gearboxes. A Technical Report is purely informative
Many beginners confuse this standard with others. Here is a quick comparison:
| Standard | Focus | What it Calculates | | :--- | :--- | :--- | | ISO 6336 (Parts 1-6) | Tooth bending and contact fatigue (pitting resistance) | Gear life in hours (mechanical strength) | | ISO TR 14179-1 | Scuffing (micro-welding) | Load limit before adhesive wear | | ISO TR 14179-2 | Thermal capacity | Maximum continuous power without overheating | | AGMA 925 A03 | Thermal rating (American standard) | Similar to ISO TR 14179-2 but with different constants |
If you only calculate mechanical strength (ISO 6336) but ignore thermal capacity, your gearbox may be mechanically sound but will burn up in the first hour of continuous use.
A: Contact ISO or your national standards body. Some allow student discounts (typically 20-30% off). Never download from torrent sites – the 2001 draft is obsolete. Part 2 provides empirical formulas for no-load losses
Not every engineer needs to perform the calculations manually. Many gear sizing software packages (like KISSsoft, MITCalc, or Romax) integrate ISO TR 14179-2. However, you still need to know the input parameters:
| Parameter | Description | Why it matters | | :--- | :--- | :--- | | Ambient temperature | Temperature around gearbox | Lower ambient = more thermal capacity | | Altitude | Above sea level | Reduced air density reduces cooling | | Type of lubrication | Splash, forced, or oil-mist | Affects churning losses | | Housing design | Cast iron vs. aluminum | Aluminum dissipates heat better | | Service factor | Duty cycle (continuous vs. intermittent) | Intermittent duty allows peak overload |
The PDF contains detailed annexes with correction factors for unusual conditions (e.g., dusty environments, high humidity).